.tab {
  font-size: 20px;
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 60px;
  display: flex;
  justify-content: space-evenly;
  padding-top: 20px;
  box-sizing: border-box;
  background-color: #fff;
  padding-bottom: 90px; //预留出安全距离

  div {
    display: flex;
    flex-direction: column;
    font-size: 14px;
    color: #666;
    text-align: center;

    img {
      width: 30px;

    }
  }
}